The measurement of biological indicators is of interest for a variety of medical disorders. Various systems have been developed to measure biological indicators from within the living body of various animals (e.g. mammals) via an implantable device.
Existing implantable devices have the potential to create high local temperatures inside the living body. Often power provided from external sources results in an increase in local temperature around the implantable device. Often transmission of information from the implantable device results in an increase in local temperature around the implantable device
The living body, however, cannot tolerate high internal temperatures. High internal temperatures often lead to tissue death. (Seese, “Characterization of tissue morphology, angiogenesis, and temperature in the adaptive response of muscle tissue in chronic heating, Lab. Invest. 1998; 78 (12): 1553-62).
Another issue facing implantable devices is the formation of a foreign body capsule in the tissue of the living body around the implantable device. Fibrogen and other proteins bind to the device surface shortly after implantation in a process known as biofouling. Macrophages bind to the receptors on these proteins releasing growth factor β and other inflammatory cytokines. Procollagen is synthesized and becomes crosslinked after secretion into the extracellular space gradually contributing to formation of a dense fibrous foreign body capsule. The dense capsule prevents the implantable device from interfacing with the living body and thereby often hinders the operation of the implantable device (Ward, “A Review of the Foreign-body Response to Subcutaneously-implanted Devices: The Role of Macrophages and Cytokines in Biofouling and Fibrosis”, Journal of Diabetes Science and Technology, Vol. 2, Is. 5, September 2008).